Alignment and retention hardware for folding doors

ABSTRACT

Hardware assemblies for aligning and retaining one or more pairs of folding doors, shutters or panels in coplanar condition employing yieldably interfitting male plunger and female socket elements mounted in bored mounting openings formed inwardly of opposing door edges to be aligned, or alternatively face mounted to operate between such edges, with the cooperating elements of the hardware assemblies having detent means for maintaining such elements in interengaged latched condition until positively removed therefrom by action of the operator.

United States Patent [191 Smith Sept. 23, 1975 ALIGNMENT AND RETENTION HARDWARE FOR FOLDING DOORS [76] Inventor: Lester L. Smith, 5151 Mission Hills Dr., Tucson, Ariz. 85718 [22] Filed: Apr. 29, 1974 21 Appl. No.2 465,235

[52] US. Cl. 160/118; 292/74; 292/76;

292/DIG. 39; 16/1; 160/206 [51] Int. Cl. E06B 3/48 [58] Field of Search 160/118, 199, 206; 16/1;

292/17, 19, 74, 76, 300, DIG. 39; 24/107, 201 S, 208 R, 208 A, 213 R, 213 CS, 230 SL, 230 AM, 230 AN [56] References Cited UNITED STATES PATENTS 1,075,028 10/1913 Frost 292/74 2,967,322 l/l961 Hollansworth 16/1 3,014,744 12/1961 Craik 292/17 3,329,990 7/1967 Johnson 16/1 3,466,075 9/1969 Fernandez 292/19 Primary Examiner-Richard J. Scanlan, Jr. Attorney, Agent, or Firm-McCaleb, Lucas & Brugman [57] ABSTRACT Hardware assemblies for aligning and retaining one or more pairs of folding doors, shutters or panels in co planar condition employing yieldably interfitting male plunger and female socket elements mounted in bored mounting openings formed inwardly of opposing door I edges to be aligned, or alternatively face mounted to operate between such edges, with the cooperating elements of the hardware assemblies having detent means for maintaining such elements in interengaged latched condition until positively removed therefrom by action of the operator.

4 Claims, 16 Drawing Figures US Patent Sept. 23,1975 Sheet 2 of 3 3,907,021

ALIGNMENT AND RETENTION HARDWARE FOR FOLDING DOORS BACKGROUND OF THE INVENTION Folding panel installations, utilizing one or more pairs of hingedly interconnected doors, one in each pair of which is normally supported about a vertical pivot axis and the other of which is guided by an overhead track for lateral movement across a door opening, are well known. Similarly, folding panel installations employing two or more hingedly interconnected panels, are familiarly used for interior window installations.

In such folding panel installations, it is desirable to provide means for aligning and retaining the panels in coplanar condition when the same are positioned in a closed condition overa door or window opening. In the case of folding doors, the typical means for this purpose is generally in accordance with the teachings of US. Pat. No. 3,351,973, issued Nov. 14, 1967 or some variation thereof. In general, such known alignment hardware systems employ a pair of protruding fingers which reach across the opposing edge junction of adjacent inboard panels in a four panel bifold door installation, for example. By and large, bifold door installations using only two folding door panels do not employ such alignment means although systems of the order found in U.S. Pat. No. 3,536,120, issued Oct. 27, 1970 are frequently used to hold two or four panel installations in closed position by resilient spring forces applied against their pivot centers. In the case of interior shutters, little or no alignment devices are known. However, familiar hasps or latch hooks often are used to keep such shutters in closed position and indirectly they may be considered to assist in aligning and retaining the shutters in generally coplanar condition across a window opening.

In practice, the above briefly described alignment systems and retention means of the prior art are not totally satisfactory and consequently need for improved hardware for the alignment and retention of such panels is evident. In the case of bifolding door alignment and retention hardware presently known, for example,

aligning and retaining only the inboard track guided door panels of a four or more panel installation as taught in US. Pat. No. 3,351,973 fails to prevent the hinged pairs of panels from partially opening about their interhinged axes when closing the door pairs simultaneously or sequentially over a closet opening. This occurs because the compression of the atmosphere within the closet serves to exert an outward pressure on the doors and hinge them partially open.

Similarly, the use of the spring biased pivot center hardware of the order found in U.S. Pat. No. 3,536,120

can and often does result in an eventual loosening and misalignment of the pivot supporting hardware and, on

occasion, may require excessive force to close the doors, against the applied spring forces.

1 SUMMARY AND OBJECTS OF THE INVENTION invention are primarily constructed for mounting in accurately formed mounting sockets bored inwardly of the opposing door edges to greatly simplify installation requirements and to reduce labor cost. In addition the cooperable elements are also mountable in opposing edges of adjacent interhinged panels to resiliently interfit with the detent means upon the closed positioning of such panels and yieldably maintain the same in coplanar position. A modified form of the retention hardware further is adapted to be face mounted on the rearward face of adjacent panels and such include cooperable interfitting male and female elements which are resiliently interfitted by closing action or movement of the door panels whereby the same operate to maintain the panels in coplanar alignment.

Among the important objects of this invention is the provision of improved hardware assemblies for aligning and resiliently retaining folding door panels in coplanar condition across a frame opening.

Another object of this invention is to provide alignment hardware assemblies for folding doors and panels having guide means for aligning and yieldably interlocking a pair of interhinged panels in coplanar condition at their opposingly adjacent interhinged edges.

Still another object of this invention is to provide improved alignment and retention hardware means for use with folding doors, panels, shutters and the like which are operable for yieldably retaining or latching the non-hinged, track guided edge of one of a pair of interhinged panels in closed position with a stationary structural frame element of the surrounding opening over which the panels are mounted.

Still another object of this invention is to provide alignment and retention hardware for folding doors, shutters and similar panels having elements mounted in mounting sockets formed in adjacent edges of such panels and which elements cooperate to align and yieldably retain such panels in coplanar condition in response to closing movement thereof.

Having thus described the invention, the above and further objects, features and advantages thereof will appear to those familiar with the art from the following detailed description of a preferred embodiment and modification thereof as illustrated in the accompanying drawings; such embodiments representing the best mode presently contemplated for enabling those skilled in this art to practice this invention.

In the drawings FIG. 1 is a front elevational view of a typical four panel bifolding door installation employing hardware assemblies according to this invention;

FIG. 2 is an enlarged cross sectional view taken substantially along vantage line 22 of FIG. 1 and looking in the direction of the arrows thereon;

FIG. 3 is an enlarged cross sectional view with parts in elevation showing a male projection member of the alignment hardware assembly mounted in a door edge;

FIG. 4 is a left hand end view thereof;

FIG. 5 is a right hand end view thereof;

FIG. 6 is an elevational view similar to FIG. 3 showing a female socket member of the alignment hardware assembly in mounted position in a door edge;

FIG. 7 is a right hand end view thereof;

FIG. 8 is an elevational view of the male projection member employed with the retention hardware assembly of this invention;

FIG. 9 is an end elevational view thereof;

FIG. 10 is a perspective view of the body member employed with the retention hardware assembly and for housing the male projection element illustrated in FIG. 8;

FIGS. 11 and 12 are operational views ofa pair ofbifolding panels illustrating the operation of the alignment and retention hardware assemblies of this invention;

FIG. 13 is an elevational view, similar to FIG. 1, illustrating the features of the modified retention hardware 1 assembly according to this invention;

FIG. 14 is an enlarged cross sectional veiw taken substantially along vantage line 1414 of FIG. 13 and looking in the direction of the arrows thereon;

FIG. 15 is an elevational view of the body member employed in the modified assembly in FIG. 14; and

FIG. 16 is an end elevational view thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the exemplary embodiment of the invention shown in the accompanying drawings for illustrative purposes, reference is made to FIG. 1 illustrating a familiar four panel bifold door installation wherein a wall 20 has a door opening 21 of rectangular configuration and which, for example, may comprise the entrance to a closet. It is to be understood, of course, that depending on the width of opening 21, either one, two or more pairs of panels, such as 22, 23, 24 and 25, may be employed to provide a closure for the door opening.

Structurally the door opening 21 is bordered by a horizontal top lintel 26, parallel vertical jambs 27 and 28 along its lateral margins and a bottom sill or floor 29. Extending across the top of the door opening and supported by the lintel 26 is a guide track 30, usually constructed of metal such as extruded aluminum and having a section providing a roller retaining track support for guide assemblies 31 associated with the inboard panels 23 and 24 in the illustrated four panel installation. While not encompassing all of the movements thereof, the edges 32 and 33 of the panels 23 and 24, respectively, are guided by an assembly 31 along the linear path of movement defined by the guide rail and thus may be referred to as linearly movable edges" thereof.

Each pair of panels such as panels 22, 23 and 24, 25 are interconnected at their adjacent margin edges (such as edges 34 and 35 of panels 22 and 23) by top and bottom hinge assemblies 36 and 37, respectively, which may be of the order set forth in my copending application, Ser. No. 335,231, filed Feb. 23, 1973, or other suitable hinges known for this purpose in the art. The hinges 36 and 37 define an axis of hinging movement for the individual panels of each pair relative to one another. Such hinging movement of the panels is indicated by the showing in FIGS. 11 and 12.

Spaced inwardly of the edges of the outboard panels 22 and 25 which lie closest to the jamb members 27 and 28 of the door opening framework, are top and bottom pivot assemblies 39 and 40, respectively; the top assembly 39 being supported in a pivot block (not shown) mounted in the guide track 30 and the bottom pivot assembly 40 being fastened to one of the jamb members and the floor or bottom sill 29 in a known manner. Pivot assemblies 39 and 40 define a vertical axis of pivotal movement for the outboard panels 22 and 25 and such pivotal support in conjunction with the interhinged connection of adjacent panels plus the linear movement of the inboard panels as required by the tracking of the guide assemblies 31 along the overhead track 30, regulate and definethe pattern of movement for the panels across the door opening 21. By virtue of this arrangement of pivots, hinges and guide assemblies, the panels are in flush and generally coplanar relationship to effect closure of the door opening 21. Knobs or handles 42 are generally provided on the exterior faces, near the midregions of the pivotallysupported panels 22 and 25 to permit application of pulling force on such panels to effect swinging action thereof about the axes of the assemblies 39 and 40. This produces resultant interhinging movement between adjacent panels of each pair about the hinge assemblies 36 and 37 to move the door to an open position (see the dotted line shown in FIG. 1 l The advantage of such a bifolding arrangement, of course, lies principally in the fact that the opening movements of the panels take considerably less room than that required for a conventionally hinge mounted door while affording the same, or nearly the same, access to the door opening when the panels are in open position.

Inasmuch as the present invention is concerned primarily with improved means for positioning and maintaining the panels in a desired coplanar condition when the same are closed over a door opening, the description which follows will principally concern alignment and retention hardware assemblies of this invention as indicated at 45 and 46, respectively, in FIG. 1 of the drawings.

Turning now to the features and particulars of the improved alignment hardware assembly 45 according to this invention, initial reference is made to FIGS. 2 through 7 which demonstrate the structural features and aspects thereof. As shown in FIG. 2, the assembly 45 comprises a male projection member or subassembly 48 and a female socket member or subassembly 49 mounted in coaxially aligned and opposing cylindrical mounting sockets 50, 51 bored inwardly of the opposing adjacent edges 34 and 35, respectively, of each pair of hingedly interconnected panels 22, 23, for example. Formation of such bored mounting sockets is according to presently known practice and'is usually conducted in a jig boring machine under factory or assembly line conditions whereby the formation of such mounting sockets is accurate and rapid.

With particular reference to FIGS. 3, 4 and 5 of the drawings, the features of the male projection member 48 will now be described. In the preferred form therein illustrated, member 48 comprises a unified molding of thermoplastic material to include a generally cylindrical body portion 52 having a length substantially equal to that of the mounting socket therefor, but with slight clearance axially. One end of the body portion 52 is distinguished by an enlarged cylindrical collar or flange portion 53 adapted to extend radially beyond the outer end of the bored mounting socket 50 to engage or set in the edge 34 of the associated door panel 22 in its mounted position therewith. Projecting coaxially outwardly of the collar portion 53 is a male projection element 54 having a conically tapered outer end 55 which merges with a cylindrical central portion 56, the latter being undercut or chamfered to form a locking neck portion 57 adjacent the flange portion 53 as shown in FIG. 3.The projection element 54 is longitudinally split in quadrants by a pair of diametrically ex 4) whereby the quadrant seqments so formed may be resiliently biased radially toward one another when entering and leaving the female socket member in operation, as will appear presently.

The body portion 52 of the male projection member 48 is formed as a hollow cylinder to promote economy of material utilization and to that end is provided with an open inner end as indicated at 60 in FIG. 3. The exterior cylindrical wall of body portion 52 is distinguished by a pair of lengthwise extending ribs 62, 62 located on diametrically opposed sides thereof to engage and penetrate the cylindrical walls of the mounting socket 50 sufficiently to prevent rotation of the member 48 in its mounting socket. Additionally, in order to prevent withdrawal of the mounted member 48 from its socket 50, once the same is inserted therein, rows of projecting teeth or tangs 65 are provided on the exterior of body portion 52. It will be noted that the teeth or tangs 65 are so formed as to face or extend toward the outer flange collar 53 permitting the member 48 to be inserted readily into socket 50, but resisting withdrawal therefrom.

With reference now to FIGS. 6 and 7 of the drawings, the features of the female socket member or subassembly 49 will be described. As shown best in FIG. 6, member 49 comprises a generally cylindrical main body portion 70 having diametrically opposed rows of anti-withdrawal prongs or tangs 71 on its exterior and anti-rotational rib projections 72 in the manner employed in forming the body for the male projection member 48 above described. The interior of the body 70 is a hollow open ended chamber and preferably is made of molded plastic to include an outer flange wall 73 which is adapted to engage or set in a recess in the edge 35 of the panel 23 in which it is mounted. It is noted best from FIG. 7 that the flange wall 73 is generally cylindrical and is distinguished by a central open- ;ing 74 formed with an annular beaded rim of curvilinear cross section having a diameter slightly less than the external diameter of the central cylindrical portion 56 on the male projection element 54. With this construc* tion, entry of the projection element 54 into central opening 74 of the female socket member requires radial contraction of the male element which is afforded by the slotted openings 58 and 59 as previously described. Thus as the male projection element 54 passes axially through opening '74, it is contracted radially inwardly to pass the beaded rim of opening 74 where- ;upon the later is eventually disposed opposite the inwardly chamfered neck portion 57 of the male projection member. At this point the split body of the projection member expands radially outwardly to its normal noncontracted condition to lock over the beaded rim or lip of opening 74 which acts as a detent means to re- With particular reference to FIG. 11, it will be recognized that the alignment hardware assembly 45 responds to the opening hinging; action-of the door panels 22 and 23 to resiliently withdraw the male projection member from the female socket or member as the door panels are opened. Conversely, FIG. 12 illustrates the condition of interengaging such sub-assemblies or members in response to the closing movement of the door panels. In this latter respect it will be appreciated that the conically tapered. outer end portion 55 of the male projection element readily assists entry of the latter into the central rimmed opening 74 of the female socket member and that such entry is culminated with the detent interlocking of the fitting members when the doors are disposed in coplanar closed condition in the manner demonstrated in FIGS. 1 and 2 of the drawings. Because of this operational interlocking of the fitting members or sub-assemblies of the hardware assembly 45, it will be readily understood and recognized by those familiar with the art that a positive system or means is provided thereby for maintaining the door panels 22 and 23 in coplanar condition until positively removed therefrom by force application from the operator. In this respect while the fitting assembly 45 is hereinabove referred to primarily as an alignment assembly, it also bears certain features of a retention means as well.

Turning now to the specifics and features of the retention assembly 46 according to this invention, particular reference is made to FIGS. 1, 2 and 10 of the drawings. As best shown in FIG. 1, assembly 46 comprises a pair of cooperating sub-assemblies, namely a male projection sub-assembly and a female socket subassembly 81 adapted to be respectively mounted in opposing cylindrical sockets 82 and 83 bored inwardly of the opposing linear movable edges 32 and 33 of the pairs of bifoldingdoor panels. Preferably assembly 46 is located adjacent the lower end or margins of panels 23 and 24 in the manner illustrated in FIG. 1.

The male projection assembly 80 comprises a twopart cylindrical housing 85 shown in exploded perspective in FIG. 10 as comprising a pair of interfitting semicylindrical half s'hell portions 86 and 87; each having a semi-cylindrical interior closed over at one end by an inner end wall portion 88. The opposite end thereof is formed with a semi-cylindrical bearing wall or collar portion 89 formed concentrically of a radially extending flange wall portion 90 which projects radially beyond the exterior of its associated shell portions 86 or 87. Opposing interfaced walls 91, 92 of the half shell portions are distinguished by interfitting sockets and projections 93 and 94, which closely interfit in assembly of the half shell portions to formulate a cylindrical housing. The exterior cylindrical walls of the housing formed by the assembled half shells 86 and 87 are provided with projecting half-teeth 95 to form retention tangs facing toward the outer flange wall 90 and two or more longitudinally extending; anti-rotational ribs 96. Thus inserting the housing assembly into the mounting socket 82 formed inwardly of the panel edge 32 in the manner illustrated in FIG. 1, serves to lock such housing in its mounting socket and prevent the same from rotating therein.

As best illustrated in FIG. 2 of the drawings, the housing 85 of assembly 80 journals a compression spring 99 and a male projection element 100, the latter which is best illustrated in FIGS. 9 and 10 of the drawings. More specifically, the male projection element 100 as best shown in FIG. 8, is formulated in many rcspects similar to the projection element of the alignment hardware assembly hereinabove described and includes a conically tapered outer end portion 101 which merges into a larger cylindrical central portion 102 interrupted by a radially inset cylindrical collar portion 103 and frusto-conical neck 104 extending between portion 103 and the outer surface of the cylindrical portion 102. An enlarged cylindrical retainer flange portion 105 of a diameter substantially equivalent to the interior diameter of the housing 85 is formed axially adjacent the inset shoulder portion 103 for retaining and guiding element 100 in the housing 85. The outer right hand end of male projection element 100 is further formed with a cylindrical inset shoulder portion 106 which coaxially receives one end of the compression spring 99 thereover in assembly (see FIG. 2). Importantly, the diameter of the portion 102 is slightly smaller than the opening at the cylindrical bearing portions 89 formed by intermating the two half shells 86 and 87 so that the portion 102 is free to pass through the bearing wall opening in operation. As with the male projection member of the alignment assembly, right angularly related and diametrically extending slotted openings 107 and 108 preferably are cut through the male projection element to provide resilient radial movements to the four quadrants created thereby.

It will be recognized from FIG. 2 in particular that with the projection element 100 mounted in the housing 85 so that the spring means 99 extends between the rear wall 88 of the housing assembly and the retainer flange portion 105 of the projection element, the latter is free to move axially of the housing, that is, inwardly of the hollow interior thereof, compressing the spring means 99 or reversibly in response to the thrusting action of such spring means to project beyond the flange wall 90 for entry into the female socket member 81 of the retention assembly.

An examination of FIG. 2 of the drawings, in particular, will demonstrate that the female socket assembly 81 is identical to the female socket assembly 49 employed with the alignment assembly heretofore described and therefore will not be described again except to point out that the entry opening in the outer end of the female socket assembly 81 is formed with the detent rim for underengaging the chamfered surface 104 and or inset shoulder portion 103 upon full entry of the male projection element into the hollow interior of the female socket when the door pairs are brought together in coplanar condition, in the manner illustrated in FIG. 2.

It will be appreciated that with the spring biasing arrangement provided in the retention assembly as above set forth, closing'operation of the doors as shown in FIG. 12, causes the male projection member to be biased inwardly against the force of spring member 99 until the same lies opposite the female socket member whereupon the force of the compressed spring thrusts the male projection element into the socket assembly 81. This positively aligns and retains the lower ends of the doors in coplanar condition; it being recalled that the linearly movable edges 32 and 33 of the door pairs are generally guided to a coplanar state near their upper ends by virtue of the track guide assemblies 31. Once the male projection member is aligned in the socket assembly 81, the doors are positively retained in coplanar closed alignment by operation of the detent latching system afforded by the interengaging detent portion (corresponding to rim opening 74 of assembly 49) and the inset shoulder or undercut portions 103, 104 of the male projection element. Because of the spring biased action and the ability of the male projection element to move axially of its housing, during the closing operation of the doors as illustrated in FIG. 12, the projection element is biased inwardly in a ready fashion when the outer end thereon engages the edge 33 of the opposing adjacent door or panel, for example. Thereafter the portion 101 seeks out the female socket opening as the doors approach their closed condition. Because of the tapered configuration of the outer end for the male projection element, such readily enters the female socket opening, guiding the male element into interengagement therewith for eventual interlocking of the mating parts. In practice, even with extreme warped condition of the doors, little or no difficulty is experienced in interfitting the retention members in the manner above described, since eventual interfitting of the cooperating elements can be achieved by manually pressing the adjacent doors toward coplanar condition; the spring force behind the male projection element being sufficient to cause the same to readily enter the female socket member as they come into near alignment.

With particular reference now to FIGS. 13 through 16 of the drawings, the features of a modified retention assembly 114, there illustrated, will now be described. As best shown in FIG. 13, for example, a facemounted assembly 114 is provided for attachment to the rear face of the inboard panels 23 and 24 adjacent the lower bottom margins thereof. While the operation of the assembly 114 is similar to that described for assembly 46 hereinabove described it has certain advantages over the latter in that it avoids the need for bored mounting sockets and is less apparent to the operator by virtue of its mounting on the rearward or inside faces of the panels which are normally out of sight.

The assembly 114 in general comprises a male projection fitting 115 and a female socket fitting 116. The male fitting is made up of a housing 117, compression spring 118 and male projection element 119. It will be understood that the projection element and spring are the same as above described and employed in assembly 46. The housing 1 17 on the other hand differs from the socket mounted housing 85 in certain aspects.

Principally housing 1 17, like housing 85, has a hollow cylindrical body member 120, having an opening 121 at one end for passage of the projection element 119. A threaded or glued in cap 122 closes over the rear end of the housing after assembly of element 119 and spring 118 therein. Two mounting pads or feet 123, 123 extend laterally outward of housing body adjacent the end thereof having opening 121, while a third pad 124 extends outwardly of the opposite end thereof. Mounting screws 125 pass through the pads 123 and 124 to secure the housing to the rear face of a door panel, such as panel 23 illustrated, so that the outer tapered end of the male element lies outwardly over the rear face of an adjacent panel 24 to be aligned with panel 23.

As in assembly 46, the male projection element 119 of this modified assembly moves axially of housing 117 with and against the force of spring 118.

The female socket fitting 116, differs materially from its counterpart in assemblies 45 and 46, and comprises a generally semi-cylindrical body 126 having a conical recess 127 in one end face thereof. Two laterally projecting mounting pads or feet 128, 128 are formed integrally with body 125 and mounting screws 129 are used to fasten the feet to the rear face of door panel 24, laterally inwardly of edge 34. The recess 126 coaxially opposes and receives the male projection element 1 19 in operation.

As with assembly 46 previously described, the male fitting member 119 enters the conical alignment socket 126 of the female member as to two doors 23 and 24 approach one another. The pressure of spring 118 serves to resiliently maintain element 119 coaxially in the socket recess 127 and thereby retain the doors in coplanar aligned condition.

From the foregoing, it is believed that those familiar with this art will readily recognize and appreciate the novel retention and alignment features of the hardware assemblies according to this invention. Further, while the illustrative embodiment has been described in the context of four bi-folding doors, the harware thereof is equally applicable to use with shutter or other panel types. In addition, both of the assemblies 45 and 46 are useful with a single pair of folding door or shutter panels. Thus the female socket element of the retention hardware assembly 46 is adapted to be mounted in a socket formed in a stationary structural element, such as a side jamb member of a door or window frame. Consequently the retention hardware of this invention is readily useful in the two-panel situation. A similar observation is true with respect to the alignment hardware assembly 45 which obviously is useful with and between adjacent interhinged panels, whether they bedoors, shutters or panels of another nature.

It is to be understood that while the hereinabove described and illustrated form of the present invention is a presently preferred example of the same, various changes, modifications and substitutions may be incorporated therein without departing from the teachings and concepts taught herein as defined in the following appended claims:

I claim:

1. In a folding door installation, the combination comprising: pair of door jambs having opposing vertical edges and a horizontal guide track therebetween, one or more pairs of parallel aligned folding door panels mounted for lateral opening and closing movements between said door jambs the panels of each pair being hingedly interconnected between adjacent opposing vertical edges, with one panel having one vertical edge supported for pivotal movement on one of said door jamb edges and the other panel vertical edges supported for pivotal and horizontal movement along said track and plural alignment assemblies mounted in at -least some of said opposing edges for aligning and retaining the panels in coplanar closed condition between said jambs, each said assembly comprising a female socket member, and a cooperating male projection member; each member having a cylindrical housing portion inserted into one of a pair of mating mounting sockets formed therefor in opposing substantial coaxial alignment inwardly of said opposing edges each said socket member having an axial chamber open at one end, and detent means formed at the entry of said chamber; a projection element of each said projection member extending outwardly from one end of its said housing portion to protrude outwardly of a panel edge in which the same is mounted and adapted to enter the open end of a said chamber of an opposing said socket member upon coplanar positioning of adjacent panels, resilient cam means on each. projection element for aligning and detachably engaging said detent means of a cooperating said socket member thereby to removably interlock adjacent panels in coplanar condition; means retaining the said projection element of each projection member mounted in a panel edge in its said housing portion, and the said projection element of each projection member mounted in a horizontally movable panel edge being movable coaxially of its housing portion, and spring means normally biasing said movable projection element outwardly of its said housing portion and permitting the same to resiliently retract thereinto upon closing engagement with an opposing edge until cammed into alignment by a cooperating said socket member for entry thereinto; said pairs of projection and socket members cooperating upon further closing movement of the door panels to align and removably retain the same in coplanar condition and tang and rib means extendling outwardly of the exterior of each said housing portion to prevent its rotation and withdrawal from its mounting socket.

2. The combination of claim 1 wherein the housing portion associated with said movable projection element encases the latter and said spring means and is of bipart construction.

3. In a folding door installation, the combination comprising: a pair of panels hingedly interjoined between adjacent edges, and a hardware assembly for aligning and retaining said panels in coplanar condition, said assembly comprising a male projection member, and a female socket member, each said member comprising a cylindrical body portion coaxially mounted in a blind bore socket formed inwardly of a said adjacent edge of each said panel for movement therewith said body portion having means projecting radially therefrom anchoring said body portion in said bore socket said mounting sockets being coaxially aligned in the coplanar position of said panels; the body portion of said socket member having a hollow interior chamber open at one end, a rigid projection element protruding outwardly of one end of the said body portion of said projection member for passage through the open end of said chamber in response to hinging movement of said panels to coplanar position, and detent means for removably locking said projection element in said chamber.

4. The combination of claim 3 wherein said detent means comprises an annular rim projecting radially inwardly about the open end of said chamber for interfering with the passage of said projection element thereinto, said projection element having a central portion of cross sectional dimension greater than the opening of said rim and being formed to contract radially when engaged by said rim in moving past the same and to expand radially outwardly once past said rim thereby to interlock said members.

UNITED STA'RES PATENT ()FFICE CERTIFICATE OF CURRECTION PATENT NO. 1 3,907,021 I DATED 3 September 23, 197 5 'NVENTOR(S) I Lester L. Smith It is certified that error appears in the ab0ve-identified patent and that said Letters Patent are hereby corrected as shown below: 6

Col. 9, line 56 (claim 1), after "track", insert semi-colon Col. 9, line 64 (claim 1), after "edges", insert semi-colon Col. 10, line 25 (claim 1) after "condition", insert comma Col. 10, line 42, (claim 3) after "therewith", insert comma Col. 10, line 44, (claim 3), after "socket", insert comma Signed and Scaled thus twentieth D of January 1976 [SEAL] Arrest:

RUTH CJMASON c. MARSHALL DANN A resfiflg Offi Commissioner uj'latents and Trademarks 

1. In a folding door installation, the combination comprising: pair of door jambs having opposing vertical edges and a horizontal guide track therebetween, one or more pairs of parallel aligned folding door panels mounted for lateral opening and closing movements between said door jambs the panels of each pair being hingedly interconnected between adjacent opposing vertical edges, with one panel having one vertical edge supported for pivotal movement on one of said door jamb edges and the other panel vertical edges supported for pivotal and horizontal movement along said track and plural alignment assemblies mounted in at least some of said opposing edges for aligning and retaining the panels in coplanar closed condition between said jambs, each said assembly comprising a female socket member, and a cooperating male projection member; each member having a cylindrical housing portion inserted into one of a pair of mating mounting sockets formed therefor in opposing substantial coaxial alignment inwardly of said opposing edges each said socket member having an axial chamber open at one end, and detent means formed at the entry of said chamber; a projection element of each said projection member extending outwardly from one end of its said housing portion to protrude outwardly of a panel edge in which the same is mounted and adapted to enter the open end of a said chamber of an opposing said socket member upon coplanar positioning of adjacent panels, resilient cam means on each projection element for aligning and detachably engaging said detent means of a cooperating said socket member thereby to removably interlock adjacent panels in coplanar condition; means retaining the said projection element of each projection member mounted in a panel edge in its said housing portion, and the said projection element of each projection member mounted in a horizontally movable panel edge being movable coaxially of its housing portion, and spring means normally biasing said movable projection element outwardly of its said housing portion and permitting the same to resiliently retract thereinto upon closing engagement with an opposing edge until cammed into alignment by a cooperating said socket member for entry thereinto; said pairs of projection and socket members cooperating upon further closing movement of the door panels to align and removably retain the same in coplanar condition and tang and rib means extending outwardly of the exterior of each said housing portion to prevent its rotation and withdrawal from its mounting socket.
 2. The combination of claim 1 wherein the housing portion associated with said movable projection element encases the latter and said spring means and is of bipart construction.
 3. In a folding door installation, the combination comprising: a pair of panels hingedly interjoined between adjacent edges, and a hardware assembly for aligning and retaining said panels in coplanar condition, said assembly comprising a male projection member, and a female socket member, each said member comprising a cylindrical body portion coaxially mounted in a blind bore socket formed inwardly of a said adjacent edge of each said panel for movement therewith said body portion having means projecting radially therefrom anchoring said body portion in said bore socket said mounting sockets being coaxially aligned in the coplanar position of said panels; the body portion of said socket member having a hollow interior chamber open at one end, a rigid projection element protruding outwardly of one end of the said body portion of said projection member for passage through the open end of said chamber in response to hinging movement of said panels to coplanar position, and detent means for removably locking said projection element in said chamber.
 4. The combination of claim 3 wherein said detent means comprises an annular rim projecting radially inwardly about the open end of said chamber for interfering with the passage of said projection element thereinto, said projection element having a central portion of cross sectional dimension greater than the opening of said rim and being formed to contract radially when engaged by said rim in moving past the same and to expand radially outwardly once past said rim thereby to interlock said members. 